The performance of facilities can be measured in relation to several criteria including the costs and benefits of alternative locations, building systems, furnishings and interior designs. The present research focuses on one facet of performance evaluation, namely, the assessment of employees' ratings of environmental conditions within their offices and the actual and perceived effects of those conditions on personal productivity and well-being. Measures of statistical reliability are presented for two employee questionnaires that address these issues (the Ratings of Environmental Features and the Checklist of Work-Related Experiences), and research strategies for evaluating the links between facilities design, employee productivity, and organizational effectiveness are discussed.